Chlorophyll Fluorescence Imaging Temporal (CFIT) described in U.S. Pat. No. 7,112,806 B2 (the '806 patent, incorporated herein by reference), images and quantifies chlorophyll fluorescence signal patterns, which measure and indicate whether the plant under test is healthy or diseased even though indications as to symptoms are not visible to the naked eye. CFIT images and measures the biology phenomenon of transient chlorophyll fluorescence with dark-adapted plants (Kautsky Effect). With a sensitive imager, active light and computer processing of the time-dependent chlorophyll fluorescence signatures, the resulting CFIT image-datacube spatially and temporally captures fluorescence-intensity-temporal (FIT) patterns that image and quantify plant stress as described in FIGS. 2, 3 and 4 of the '806 patent. The FIT patterns are real-time measures of electron transport and cellular pH that quantify the plant's photosynthetic response to plant stress. Eighteen different FIT patterns that relate to types and stages of plant health and pre-symptom plant stress have been identified in laboratory testing; such are disclosed in the '806 patent incorporated herein by reference. As the number of field crop applications and biotic and abiotic stressors increase, the number of foliar FIT patterns that are acquired and can be stored in an imaging system plant disease database will also increase, especially for biotic stress.
When conducting a CFIT testing (in the lab, greenhouse or field) many of the FIT patterns are general and not sufficient or specific to diagnose the cause or type of disease affecting the plant. Some are more specific and indicate an environmental stress such as a saturated herbicide pattern or another as a type of heat stress pattern. For other general FIT patterns additional secondary indicators are necessary to improve the diagnosis.